"How can I remove water stains from wheel rims?" "I thought wiping them with detergent would be enough, but they're not coming off at all... I also want to know how to prevent rims from getting dirty."

Today, we'll answer those questions.
To remove dirt from rims, you need to understand the material the rim is made of and the causes of the dirt.

Therefore, this time, we will explain "the causes of water stains on rims" in addition to "how to remove water stains."
By referring to this article, you can remove dirt without over-grinding your rims.

3 Causes of Water Stains on Wheel Rims

First, we will explain the types and causes of water stains and rust.

・Oily water stains
・Water-soluble water stains
・White rust
・Red rust
As listed above.
If the stains do not come off with water and detergent, it is highly likely to be white rust.

Oily Water Stains

Water stains on bicycles are largely due to debris flying off cars and chain oil. Therefore, be especially careful when riding in the rain. Black clumps, by the way, are oily stains.

Water-Soluble Water Stains

Dust and grime in the air accumulate on the wheels, and when washed away by rain, they become white water stains. However, water-soluble stains are easy to remove, so gently wash them and rinse with water. By the way, water-soluble stains are formed by the friction between the rim and brake pads, so they will quickly reappear if you only remove the dirt.

White Rust

White rust is characterized by not coming off with methods for removing water-soluble stains, or by appearing as white spots. This rust is said to occur when plating (processed metal) is exposed to rainwater and left in a place where it doesn't dry.

Therefore, if the rim is wet, or left in a place where oil or water adheres and does not dry quickly, white rust will occur.

Red Rust

Red rust occurs when moisture on the wheel rims and other parts reacts with oxygen in the air. Therefore, make an effort to clean the rims, screws, and chain even on days when you don't ride your bicycle.

 

Materials Used for Wheel Rims

The common materials used for wheel rims are "aluminum," "stainless steel," and "carbon," and the precautions for grinding vary depending on the material.

Aluminum

If the rim is shiny, it is made of aluminum. This type of rim produces black residue when polished.

Stainless Steel

If the rim is not glossy, it is made of stainless steel. Unlike aluminum, stainless steel is not abraded by brake shoes, so there is no need to grind it forcefully (and grinding it forcefully is also not recommended).

Carbon

If the rim is made of carbon, there is no need to grind it, so simply wipe it with a cloth or towel and detergent.

[Easy] How to Remove Water Stains from Wheel Rims

・Wipe with a rag and parts cleaner
・Rub with a rubber whetstone
・Soak the rubber whetstone in water
・Final check

The method for removing water stains from wheel rims is as above.

Let's explain in detail.

How to remove water stains: Wipe with a rag and parts cleaner

First, clean the rim with parts cleaner. Any parts cleaner is fine, but be very careful with the cloth you use to wipe. Cloths that have been used to wipe the frame or have been used in the past will have some oil attached to them, so wiping with such a cloth can easily cause oily stains. Therefore, use a new cloth. After wiping, dry wipe with a new rag. Also, for cleaning thoroughly without scratches, paper rags are recommended.

How to remove water stains: Rub with a rubber whetstone

A rubber whetstone is recommended for removing water stains. There are also "Gekiochi-kun" sponges and sandpaper for removing water stains, but a rubber whetstone is the best choice for flawless removal and preventing reoccurrence of stains. "Gekiochi-kun" sponges and sandpaper may not completely remove stains due to their coarseness, or may even scratch the rim.
There are three types of rubber whetstones, and the K-141 model number is the safest. K-140 is too coarse and will cause scratches, and K-142 is not effective enough at removing dirt.

How to remove water stains: Soak the rubber whetstone in water

When grinding wheel rims with a rubber whetstone, it's good to soak the whetstone in water for about 5 minutes. Just like sharpening a knife, this prevents black residue from accumulating on the whetstone. This allows you to polish aggressively.
After grinding, apply parts cleaner to a paper rag to thoroughly remove dirt from the rim, and finally, dry wipe.

How to remove water stains: Final check

Touch the rim by hand to check for any oil or water.

Note: Rubber Whetstone

Use a HOZAN brand rubber whetstone, not a 100-yen store one. Check the product number to confirm it's "K-141." You can purchase it on Amazon for about 1000 yen. Also, if your brakes are making strange noises, a rubber whetstone is highly effective, so it's definitely worth trying.

Note: About the cleaning effect of Gekiochi-kun

There's a limit to how much dirt you can remove from a rim with a Gekiochi-kun sponge. The reason oily grime and black dirt build up on rims in the first place is that the rim gets scratched by the brake pads, and dirt accumulates there. To prevent dirt from accumulating again, you need to grind the wheel rim and polish it so that it doesn't rub against the brake pads. Therefore, before attempting to clean the rim with a Gekiochi-kun sponge, we recommend cleaning it with a rubber whetstone.

Key Points for Removing Water Stains and Dirt from Wheel Rims

Finally, let's look at the key points for removing water stains and dirt. Rims wear out faster than you might think, so be very careful when grinding.

Is a rubber whetstone better than sandpaper?

A rubber whetstone is recommended over sandpaper. There are various types of sandpaper, and one wrong move could remove too much of the rim and cause the brakes to become ineffective.

How to remove "dirt" from wheel rims

If you are uneasy about grinding the rim, you can try using a Gekiochi-kun sponge or melamine sponge. Even just wetting them with water will remove a good amount of dirt.

Wheel Rim Water Stain Causes and Solutions: Summary
・Wipe with a rag and parts cleaner
・Rub with a rubber whetstone
・Soak the rubber whetstone in water
・Final check

Sandpaper can potentially over-grind, so a rubber whetstone is recommended. However, even with a rubber whetstone, it's not foolproof, so be very careful not to over-grind.

 

〈Reference Articles〉

ICAN AERO40 Carbon Wheels - Jonhny Pink's enthusiastic review!

Chinese Carbon Wheel Buying Guide